[llvm] [llvm-readobj, ELF] Support reading binary with more than PN_XNUM segments. (PR #165278)

[via llvm-commits]

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@@ -935,9 +935,13 @@ template <class ELFT> ELFFile<ELFT>::ELFFile(StringRef Object) : Buf(Object) {}
 template <class ELFT> Error ELFFile<ELFT>::readShdrZero() {
   const Elf_Ehdr &Header = getHeader();
 
-  if ((Header.e_phnum == ELF::PN_XNUM || Header.e_shnum == 0 ||
-       Header.e_shstrndx == ELF::SHN_XINDEX) &&
-      Header.e_shoff != 0) {
+  // If e_shnum == 0 && e_shoff == 0, that means we actually have no section and
+  // thus is a valid ELF. But if the condition is still true when e_phnum ==
+  // PN_XNUM || e_shtstrndx == SHN_XINDEX and e_shoff == 0 The error will
+  // trigger when getSection() and e_shoff == 0
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aokblast wrote:

Grpahite tells me to rebase this PR since this one have already created and is not a descend of my new PR (ELF.h fix only).  Can I rebase it right now?

https://github.com/llvm/llvm-project/pull/165278